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National Ocean Service
Datums Page Page 1 of 11
Station ID: 8447435 PUBLICATION DATE: 05/20/2020
Name: CHATHAM, LYDIA COVE
MA
NOAA Chart: 13248 Latitude: 41° 41.3' N ( 41.68847)
USGS Quad: CHATHAM Longitude: 69° 57.1' W ( -69.95108)
From the intersection of state highway 28 and Main street in the village of
Chatham, proceed one block east on Main street, turn left on Seaview street and
continue 0.47 miles ( 0.76 km ) to Shore road, turn left on Shore road and go
0.22 miles (0.36 km) north on Shore road to the Chatham municipal fish pier on
the right. The bench marks are located in the vicinity of the fishing pier and
the seawall. The new orifice pipe is at the SW corner of the south most USCG
slip. This was the location of the old hydro Aquatrak well. The new MWWL
sensor is at the north end of the seawall in the slip for the harbor vessel.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 7435 B 1985
DESIGNATION: 844 7435 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 13534
AGENCY: National Ocean Service (NOS) IDB PID#: AA7166
SETTING CLASSIFICATION: Concrete pedestal OPUS PID#: AA7166
LATITUDE: 41° 41.3' N ( 41.68814) LONGITUDE: 69° 57.1' W ( -69.95151)
The primary bench mark is a disk set in the north corner of the 2 m x 2 m (6 ft
x 6 ft) concrete pedistal for electrical transformer No. 60/010 located at the
Chatham Municipal Fish Pier, 31.55 m (103.5 ft) south of the south corner of the
Nickerson Fish Market, 11.95 m (39.2 ft) east of the SE corner of the
Dockmasters Building, 4.91 m (16.1 ft) NW of a red and white fire hydrant, and
0.20 m (0.67 ft) above the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 11
Station ID: 8447435 PUBLICATION DATE: 05/20/2020
Name: CHATHAM, LYDIA COVE
MA
NOAA Chart: 13248 Latitude: 41° 41.3' N ( 41.68847)
USGS Quad: CHATHAM Longitude: 69° 57.1' W ( -69.95108)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7435 E 1985
DESIGNATION: 844 7435 E TIDAL
MONUMENTATION: Tidal Station disk VM#: 13537
AGENCY: National Ocean Service (NOS) IDB PID#: AB7971
SETTING CLASSIFICATION: Boulder OPUS PID:
LATITUDE: 41° 41.4' N ( 41.68953) LONGITUDE: 69° 57.1' W ( -69.95133)
The bench mark is a disk set on the top of a granite boulder along the beach,
116.80 m (383.2 ft) north of the NE corner of the Chatham pier fish market
building, 94.22 m (309.1 ft) north of a fence corner at the NW edge of a
concrete parking lot, 92.91 m (304.8 ft) north of the NE corner of a concrete
wall, 62.0 m (203.4 ft) south of the north end of the seawall, 55.2 m (181.1 ft)
north of a set of wooden stairs and 18.28 m (60.0 ft) south of the southernmost
set of wooden stairs.
BENCH MARK STAMPING: 7435 F 2009
DESIGNATION: 844 7435 F
MONUMENTATION: Tidal Station disk VM#: 19157
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Footing OPUS PID:
LATITUDE: 41° 41.3' N ( 41.68847) LONGITUDE: 69° 57.1' W ( -69.95108)
The bench mark is set flush in the concrete cap of the pier at the north end of
the docks and east of the Chatham pier fish market building, 22.95 m (75.30 ft)
south of the north end of the dock, 6.66 m (21.85 ft) NE of the NE corner of the
Chatham pier fish market building, 1.49 m (4.9 ft) NNE of a metal light pole,
and 0.34 m (1.12 ft) above the concrete deck.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 11
Station ID: 8447435 PUBLICATION DATE: 05/20/2020
Name: CHATHAM, LYDIA COVE
MA
NOAA Chart: 13248 Latitude: 41° 41.3' N ( 41.68847)
USGS Quad: CHATHAM Longitude: 69° 57.1' W ( -69.95108)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7435 G 2009
DESIGNATION: 844 7435 G
MONUMENTATION: Tidal Station disk VM#: 19158
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Footing OPUS PID:
LATITUDE: 41° 41.4' N ( 41.68953) LONGITUDE: 69° 57.1' W ( -69.95133)
The bench mark is a disk set on a concrete loading dock, 29.68 m (97.4 ft) NNW
of the NE corner of the fish processing plant building, 27.76 m (91.1 ft) SE of
the corner of a fence at the NW corner of a parking lot, 23.03 m (75.6 ft) SSE
of the NE corner of a parking lot, 10.56 m (34.6 ft) NNE of the SE corner of the
Chatham Pier Fish Market and 6.67 m (21.9 ft) ENE of the NE corner of the
Chatham Pier Fish Market.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 11
Station ID: 8447435 PUBLICATION DATE: 05/20/2020
Name: CHATHAM, LYDIA COVE
MA
NOAA Chart: 13248 Latitude: 41° 41.3' N ( 41.68847)
USGS Quad: CHATHAM Longitude: 69° 57.1' W ( -69.95108)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: Q 57 1996
DESIGNATION: Q 57
MONUMENTATION: Flange-encased Rod VM#: 20266
AGENCY: CO-OPS IDB PID#: AB7969
SETTING CLASSIFICATION: Stainless steel rod OPUS PID#: AB7969
LATITUDE: 41° 40.9' N ( 41.68156) LONGITUDE: 69° 57.0' W ( -69.95061)
The bench mark is a flange-encased rod set in the grass near the corner of Shore
Road and a gravel driveway, 34.95 m (114.7 ft) north of a fire hydrant, 34.50 m
(113.2 ft) SE of power pole 47v215, 32.57 m (106.9 ft) south of the SW corner of
a garage, 7.38 m (24.2 ft) ENE of the center line of Shore Road, 4.94 m (16.2
ft) south of the center line of the gravel driveway to 166 Shore Road, 0.40 m
(1.3 ft) WSW of a carsonite post. The datum point is set 10 cm (4 inches) below
ground, being the top of a stainless-steel rod, encased in a 7.25-in (18 cm) NPS
logo cap.
BENCH MARK STAMPING: 7435 J 2017
DESIGNATION: 844 7435 J
MONUMENTATION: Flange-encased Rod VM#: 23130
AGENCY: National Park Service IDB PID:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID#: BBGQ20
LATITUDE: 41° 41.3' N ( 41.68892) LONGITUDE: 69° 57.2' W ( -69.95258)
The bench mark is a flange-encased rod set in the grass near the SW corner of
Barcliff Avenue and Shore Road, 32.91 m (108.0 ft) NNW of power pole number 42,
26.78 m (87.9 ft) SE of a power pole, 26.50 m (86.9 ft) 86.9 ft) WNW of a street
lamp, 18.20 m (59.7 ft) SSE of a fire hydrant, 17.14 m (56.2 ft) SW of a power
pole, 8.78 m (28.8 ft) SSW of the center line of Barcliff Avenue and 7.43 m
(24.4 ft) west of the center line of Shore avenue. The datum point is set 8 cm
(3 inches) below the ground, encased in a 7.25-in (18 cm) NPS logo cap.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 11
Station ID: 8447435 PUBLICATION DATE: 05/20/2020
Name: CHATHAM, LYDIA COVE
MA
NOAA Chart: 13248 Latitude: 41° 41.3' N ( 41.68847)
USGS Quad: CHATHAM Longitude: 69° 57.1' W ( -69.95108)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7435 K 2017
DESIGNATION: 844 7435 K
MONUMENTATION: Flange-encased Rod VM#: 23131
AGENCY: National Park Service IDB PID:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID:
LATITUDE: 41° 41.1' N ( 41.68447) LONGITUDE: 69° 57.3' W ( -69.95442)
The bench mark is a flange-encased rod set in the grass on the south side of
Seaview St and the NE edge of a golf course, 39.15 m (128.4 ft) ENE of power
pole 18vz12, 31.18 m (102.3 ft) SSE of the SW corner of a building called Holly
Cottage, 11.40 m (37.4 ft) SW of the center line of a gravel drive, and 10.05 m
(33.0 ft) SSE of the center line of Seaview Dr, the datum point is set 10 cm (4
inches) below ground, being the top of a stainless-steel rod, encased in a
7.25-in (18 cm) NPS logo cap.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 11
Station ID: 8447435 PUBLICATION DATE: 05/20/2020
Name: CHATHAM, LYDIA COVE
MA
NOAA Chart: 13248 Latitude: 41° 41.3' N ( 41.68847)
USGS Quad: CHATHAM Longitude: 69° 57.1' W ( -69.95108)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7435 M 2017
DESIGNATION: 844 7435 M
MONUMENTATION: Tidal Station disk VM#: 23132
AGENCY: IDB PID:
SETTING CLASSIFICATION: Disk crimped to metal rod OPUS PID:
LATITUDE: 41° 40.9' N ( 41.68208) LONGITUDE: 69° 57.6' W ( -69.95925)
The bench mark is an aluminum disk set in the ground at the entrance to a civil
war memorial near the SE corner of a grassy triangle formed by Seaview St and
Main St, 33.83 m (111.0 ft) SE of a fire hydrant on the north side of Seaview
St, 28.60 m (93.8 ft) east of the SE corner of a one story building located at
613 Main St, 16.78 m (55.1 ft) SSW of a flagpole on the NE corner of Seaview St
and Main St, 11.29 m (37.0 ft) NNW of a 0.91 m (3.0 ft) stone pillar at the
southern corner of a grassy triangle formed by Seaview St and Main St, 10.21 m
(33.5 ft) SSW of a 4x4 granite base for the civil war memorial, 2.75 m (9.0 ft)
ESE of a stone pillar on the NW side of the entrance to the civil war memorial,
1.16 m (3.8 ft) NNE of a stone pillar on the SE side of the entrance to the
civil war memorial and 0.75 m (2.5 ft) NE of a concrete wall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 11
Station ID: 8447435 PUBLICATION DATE: 05/20/2020
Name: CHATHAM, LYDIA COVE
MA
NOAA Chart: 13248 Latitude: 41° 41.3' N ( 41.68847)
USGS Quad: CHATHAM Longitude: 69° 57.1' W ( -69.95108)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7435 L 2017
DESIGNATION: 844 7435 L
MONUMENTATION: Tidal Station disk VM#: 23133
AGENCY: IDB PID:
SETTING CLASSIFICATION: Disk crimped on a metal rod. OPUS PID:
LATITUDE: 41° 41.0' N ( 41.68317) LONGITUDE: 69° 57.5' W ( -69.95842)
The bench mark is a disk set in the ground near the NE corner of a parking lot
on the SW side of Main St, 29.47 m (96.7 ft) south of a fire hydrant near the NE
corner of Main St and Blackberry Lane, 26.65 m (87.4 ft) SW of the NW corner of
the building at 540 Main St, 18.97 m (62.2 ft) SE of the SE corner of the
Chatham Town Offices building, 15.69 m (51.5 ft) NW of the north corner of a
wood frame building, 10.51 m (34.5 ft) SSW of the center line of Main St and
7.80 m (25.6 ft) SE of the center line of the driveway to the parking.
BENCH MARK STAMPING: 7435 N 2017
DESIGNATION: 844 7435 N
MONUMENTATION: Tidal Station disk VM#: 23134
AGENCY: IDB PID:
SETTING CLASSIFICATION: Disk crimped to metal rod OPUS PID:
LATITUDE: 41° 41.1' N ( 41.68561) LONGITUDE: 69° 57.6' W ( -69.95981)
The bench mark is an aluminum disk set in the ground on the SE corner of
Highland Avenue and Highway 28, 25.69 m (84.3 ft) west of power pole 43/1, 14.70
m (48.2 ft) SSE of power pole 498, 12.31 m (40.4 ft) north of a flagpole near
the SE corner of Highland Avenue and Highway 28, 7.81 m (25.6 ft) SSW of the
center line of Highland Avenue, 6.72 m (22.0 ft) ESE of the center line of
Highway 28 and 6.23 m (20.4 ft) west of the NE corner of a nearby fence.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 8 of 11
Station ID: 8447435 PUBLICATION DATE: 05/20/2020
Name: CHATHAM, LYDIA COVE
MA
NOAA Chart: 13248 Latitude: 41° 41.3' N ( 41.68847)
USGS Quad: CHATHAM Longitude: 69° 57.1' W ( -69.95108)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7435 H 2017
DESIGNATION: 844 7435 H
MONUMENTATION: Flange-encased Rod VM#: 23135
AGENCY: National Park Service IDB PID:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID#: BBGQ21
LATITUDE: 41° 41.4' N ( 41.69000) LONGITUDE: 69° 57.5' W ( -69.95753)
The bench mark is a flange-encased rod set in the grass near the NE corner of
Barcliff Avenue and Old Harbor Road, 27.45 m (90.1 ft) NE of power pole 9-23,
26.63 m (87.4 ft) east of a fire hydrant, 19.52 m (64.0 ft) NE of a fire
hydrant, 13.52 m (44.4 ft) ESE of power pole 9-24, 8.74 m (28.7 ft) ESE of the
center line of Old Harbor Road, 5.96 m (19.6 ft) NNE of the center line of
Barcliff Avenue, 4.65 m (15.3 ft) SW of a flagpole on the NE corner of Barcliff
Avenue and Old Harbor Road, 1.94 m (6.4 ft) ENE of the center of a storm grate
and 1.27 m (4.2 ft) NNE of a stop sign on the SW corner of Barcliff Avenue and
Old Harbor Road. The datum point is set 10 cm (4 inches) below ground, being
the top of a stainless-steel rod, encased in a 7.25-in (18 cm) NPS logo cap.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 9 of 11
Station ID: 8447435 PUBLICATION DATE: 05/20/2020
Name: CHATHAM, LYDIA COVE
MA
NOAA Chart: 13248 Latitude: 41° 41.3' N ( 41.68847)
USGS Quad: CHATHAM Longitude: 69° 57.1' W ( -69.95108)
T I D A L D A T U M S
Tidal datums at CHATHAM, LYDIA COVE based on:
LENGTH OF SERIES: 2 YEARS
TIME PERIOD: September 2015 - August 2017
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8449130 NANTUCKET ISLAND, NANTUCKET SOUND
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (01/03/2014) = 2.881
MEAN HIGHER HIGH WATER MHHW = 1.578
MEAN HIGH WATER MHW = 1.464
MEAN SEA LEVEL MSL = 0.778
North American Vertical Datum NAVD88 = 0.760
MEAN TIDE LEVEL MTL = 0.757
MEAN LOW WATER MLW = 0.050
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (01/25/2011) = -0.703
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
7435 B 1985 4.585 3.121
7435 E 1985 2.744 1.280
7435 F 2009 2.932 1.468
7435 G 2009 3.322 1.858
Q 57 1996 12.386 10.922
7435 J 2017 13.504 12.040
7435 K 2017 15.159 13.695
7435 M 2017 5.363 3.899
7435 L 2017 9.249 7.785
7435 N 2017 15.543 14.079
7435 H 2017 19.588 18.124
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 10 of 11
Station ID: 8447435 PUBLICATION DATE: 05/20/2020
Name: CHATHAM, LYDIA COVE
MA
NOAA Chart: 13248 Latitude: 41° 41.3' N ( 41.68847)
USGS Quad: CHATHAM Longitude: 69° 57.1' W ( -69.95108)
Foot Notes:
Bench marks '7435 (H, K, L, M, N) 2017' are based on one differential leveling
connection and do not meet the quality control standards of the NOS. Therefore,
caution should be used when deriving elevations for these marks.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 11 of 11
Station ID: 8447435 PUBLICATION DATE: 05/20/2020
Name: CHATHAM, LYDIA COVE
MA
NOAA Chart: 13248 Latitude: 41° 41.3' N ( 41.68847)
USGS Quad: CHATHAM Longitude: 69° 57.1' W ( -69.95108)
D E F I N I T I O N S
Mean Sea Level (MSL) is a tidal datum determined over a 19-year National Tidal
Datum Epoch. It pertains to local mean sea level and should not be confused
with the fixed datums of North American Vertical Datum of 1988 (NAVD88).
NAVD88 is a fixed datum derived from a simultaneous, least squares, minimum
constraint adjustment of Canadian/Mexican/United States leveling observations.
Local mean sea level observed at Father Point/Rimouski, Canada was held fixed as
the single initial constraint. NAVD88 replaces NGVD29 as the national
standard geodetic reference for heights. Bench mark elevations relative to
NAVD88 are available from NGS through the World Wide Web at
National Geodetic Survey.
NGVD29 is a fixed datum adopted as a national standard geodetic reference for
heights but is now considered superseded. NGVD29 is sometimes referred to as
Sea Level Datum of 1929 or as Mean Sea Level on some early issues of Geological
Survey Topographic Quads. NGVD29 was originally derived from a general
adjustment of the first-order leveling networks of the U.S. and Canada after
holding mean sea level observed at 26 long term tide stations as fixed.
Numerous local and wide-spread adjustments have been made since establishment in
1929. Bench mark elevations relative to NGVD29 are available from the National
Geodetic Survey (NGS) data base via the World Wide Web at
National Geodetic Survey.
NAVD88 and NGVD29 are fixed geodetic datums whose elevation relationships to
local MSL and other tidal datums may not be consistent from one location to
another.
The Vertical Mark Number (VM#) and PID# shown on the bench mark sheet are unique
identifiers for bench marks in the tidal and geodetic databases, respectively.
Each bench mark in either database has a single, unique VM# and/or PID# assigned.
Where both VM# and PID# are indicated, both tidal and geodetic elevations are
available for the bench mark listed. The NGS's Integrated Data Base (IDB PID)
provides geodetic datum based on traditionally leveled and bluebooked ties to
the National Spatial Reference System(NSRS) https://www.ngs.noaa.gov/datasheets/.
The NGS Online Positioning User Service (OPUS PID) provides geodetic datum based
on GPS position & tie it to the NSRS https://www.ngs.noaa.gov/OPUS/.
The NAVD88 elevation is shown on the Elevations of Tidal Datums Table Referred
to MLLW only when two or more of the bench marks listed have NAVD88 elevations.
The NAVD88 elevation relationship shown in the table is derived from an average
of several bench mark elevations relative to tide station datum. As a result of
this averaging, NAVD88 bench mark elevations computed indirectly from the tidal
datums elevation table may differ slightly from NAVD88 elevations listed for
each bench mark in the NGS database.